@baseBg: '#fff';
@f20: 20px;
@nice-blue: #5b83ad;
@light-blue: @nice-blue + #111;
.shitihua(@w,@h,@bg:yellow) {
  // :yellow是默认值，不传参时生效
  width: @w;
  height: @h;
  background: @bg;
}
.bordered {
  border-top: dotted 5px black;
  border-bottom: solid 5px black;
}
.box {
  width: 200px;
  height: 200px;
  .cc {
    width: 100px;
    height: 100px;
    .bordered(); //混合
  }
  &:after {
    content: ' ';
    display: block;
    font-size: 0;
    height: 0;
    clear: both;
    visibility: hidden;
  }
}
@base: #f04615;
@width: 0.5;
